It suddenly occurred to me whilst reading the "Friday night in" thread that I'm actually rubbish.

It's not that I've not got friends, it's just that when it comes down to it, it only tends to be 'cos they've got the necessary social skills to keep a friendship going and/or 'cos we bump into each other at places without us having to do anything to facilitate. There's only about three people I'd ever ring to invite out for a beer and pretty much everyone else I'm friends with it's only 'cos we see each other in the same places socially.

So
a) how good are you at it?
b) how do you do it? I want to expand my social network but I'm just really uncomfortable inviting people out socially...